//========================================================================
// GLFW 3.3 - www.glfw.org
//------------------------------------------------------------------------
// Copyright (c) 2002-2006 Marcus Geelnard
// Copyright (c) 2006-2019 Camilla Löwy <elmindreda@glfw.org>
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would
//    be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
//    be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
//    distribution.
//
//========================================================================
// Please use C89 style variable declarations in this file because VS 2010
//========================================================================

#include "internal.h"

#include <assert.h>
#include <math.h>
#include <float.h>
#include <string.h>
#include <stdlib.h>
#include <limits.h>

// Lexically compare video modes, used by qsort
//
static int compareVideoModes(const void* fp, const void* sp) {
  const GLFWvidmode* fm = fp;
  const GLFWvidmode* sm = sp;
  const int fbpp = fm->redBits + fm->greenBits + fm->blueBits;
  const int sbpp = sm->redBits + sm->greenBits + sm->blueBits;
  const int farea = fm->width * fm->height;
  const int sarea = sm->width * sm->height;

  // First sort on color bits per pixel
  if (fbpp != sbpp)
    return fbpp - sbpp;

  // Then sort on screen area
  if (farea != sarea)
    return farea - sarea;

  // Then sort on width
  if (fm->width != sm->width)
    return fm->width - sm->width;

  // Lastly sort on refresh rate
  return fm->refreshRate - sm->refreshRate;
}

// Retrieves the available modes for the specified monitor
//
static GLFWbool refreshVideoModes(_GLFWmonitor* monitor) {
  int modeCount;
  GLFWvidmode* modes;

  if (monitor->modes)
    return GLFW_TRUE;

  modes = _glfwPlatformGetVideoModes(monitor, &modeCount);
  if (!modes)
    return GLFW_FALSE;

  qsort(modes, modeCount, sizeof(GLFWvidmode), compareVideoModes);

  free(monitor->modes);
  monitor->modes = modes;
  monitor->modeCount = modeCount;

  return GLFW_TRUE;
}

//////////////////////////////////////////////////////////////////////////
//////                         GLFW event API                       //////
//////////////////////////////////////////////////////////////////////////

// Notifies shared code of a monitor connection or disconnection
//
void _glfwInputMonitor(_GLFWmonitor* monitor, int action, int placement) {
  if (action == GLFW_CONNECTED) {
    _glfw.monitorCount++;
    _glfw.monitors =
        realloc(_glfw.monitors, sizeof(_GLFWmonitor*) * _glfw.monitorCount);

    if (placement == _GLFW_INSERT_FIRST) {
      memmove(_glfw.monitors + 1,
              _glfw.monitors,
              ((size_t)_glfw.monitorCount - 1) * sizeof(_GLFWmonitor*));
      _glfw.monitors[0] = monitor;
    } else
      _glfw.monitors[_glfw.monitorCount - 1] = monitor;
  } else if (action == GLFW_DISCONNECTED) {
    int i;
    _GLFWwindow* window;

    for (window = _glfw.windowListHead; window; window = window->next) {
      if (window->monitor == monitor) {
        int width, height, xoff, yoff;
        _glfwPlatformGetWindowSize(window, &width, &height);
        _glfwPlatformSetWindowMonitor(window, NULL, 0, 0, width, height, 0);
        _glfwPlatformGetWindowFrameSize(window, &xoff, &yoff, NULL, NULL);
        _glfwPlatformSetWindowPos(window, xoff, yoff);
      }
    }

    for (i = 0; i < _glfw.monitorCount; i++) {
      if (_glfw.monitors[i] == monitor) {
        _glfw.monitorCount--;
        memmove(_glfw.monitors + i,
                _glfw.monitors + i + 1,
                ((size_t)_glfw.monitorCount - i) * sizeof(_GLFWmonitor*));
        break;
      }
    }
  }

  if (_glfw.callbacks.monitor)
    _glfw.callbacks.monitor((GLFWmonitor*)monitor, action);

  if (action == GLFW_DISCONNECTED)
    _glfwFreeMonitor(monitor);
}

// Notifies shared code that a full screen window has acquired or released
// a monitor
//
void _glfwInputMonitorWindow(_GLFWmonitor* monitor, _GLFWwindow* window) {
  monitor->window = window;
}

//////////////////////////////////////////////////////////////////////////
//////                       GLFW internal API                      //////
//////////////////////////////////////////////////////////////////////////

// Allocates and returns a monitor object with the specified name and dimensions
//
_GLFWmonitor* _glfwAllocMonitor(const char* name, int widthMM, int heightMM) {
  _GLFWmonitor* monitor = calloc(1, sizeof(_GLFWmonitor));
  monitor->widthMM = widthMM;
  monitor->heightMM = heightMM;

  strncpy(monitor->name, name, sizeof(monitor->name) - 1);

  return monitor;
}

// Frees a monitor object and any data associated with it
//
void _glfwFreeMonitor(_GLFWmonitor* monitor) {
  if (monitor == NULL)
    return;

  _glfwPlatformFreeMonitor(monitor);

  _glfwFreeGammaArrays(&monitor->originalRamp);
  _glfwFreeGammaArrays(&monitor->currentRamp);

  free(monitor->modes);
  free(monitor);
}

// Allocates red, green and blue value arrays of the specified size
//
void _glfwAllocGammaArrays(GLFWgammaramp* ramp, unsigned int size) {
  ramp->red = calloc(size, sizeof(unsigned short));
  ramp->green = calloc(size, sizeof(unsigned short));
  ramp->blue = calloc(size, sizeof(unsigned short));
  ramp->size = size;
}

// Frees the red, green and blue value arrays and clears the struct
//
void _glfwFreeGammaArrays(GLFWgammaramp* ramp) {
  free(ramp->red);
  free(ramp->green);
  free(ramp->blue);

  memset(ramp, 0, sizeof(GLFWgammaramp));
}

// Chooses the video mode most closely matching the desired one
//
const GLFWvidmode* _glfwChooseVideoMode(_GLFWmonitor* monitor,
                                        const GLFWvidmode* desired) {
  int i;
  unsigned int sizeDiff, leastSizeDiff = UINT_MAX;
  unsigned int rateDiff, leastRateDiff = UINT_MAX;
  unsigned int colorDiff, leastColorDiff = UINT_MAX;
  const GLFWvidmode* current;
  const GLFWvidmode* closest = NULL;

  if (!refreshVideoModes(monitor))
    return NULL;

  for (i = 0; i < monitor->modeCount; i++) {
    current = monitor->modes + i;

    colorDiff = 0;

    if (desired->redBits != GLFW_DONT_CARE)
      colorDiff += abs(current->redBits - desired->redBits);
    if (desired->greenBits != GLFW_DONT_CARE)
      colorDiff += abs(current->greenBits - desired->greenBits);
    if (desired->blueBits != GLFW_DONT_CARE)
      colorDiff += abs(current->blueBits - desired->blueBits);

    sizeDiff = abs((current->width - desired->width) *
                       (current->width - desired->width) +
                   (current->height - desired->height) *
                       (current->height - desired->height));

    if (desired->refreshRate != GLFW_DONT_CARE)
      rateDiff = abs(current->refreshRate - desired->refreshRate);
    else
      rateDiff = UINT_MAX - current->refreshRate;

    if ((colorDiff < leastColorDiff) ||
        (colorDiff == leastColorDiff && sizeDiff < leastSizeDiff) ||
        (colorDiff == leastColorDiff && sizeDiff == leastSizeDiff && rateDiff < leastRateDiff)) {
      closest = current;
      leastSizeDiff = sizeDiff;
      leastRateDiff = rateDiff;
      leastColorDiff = colorDiff;
    }
  }

  return closest;
}

// Performs lexical comparison between two @ref GLFWvidmode structures
//
int _glfwCompareVideoModes(const GLFWvidmode* fm, const GLFWvidmode* sm) {
  return compareVideoModes(fm, sm);
}

// Splits a color depth into red, green and blue bit depths
//
void _glfwSplitBPP(int bpp, int* red, int* green, int* blue) {
  int delta;

  // We assume that by 32 the user really meant 24
  if (bpp == 32)
    bpp = 24;

  // Convert "bits per pixel" to red, green & blue sizes

  *red = *green = *blue = bpp / 3;
  delta = bpp - (*red * 3);
  if (delta >= 1)
    *green = *green + 1;

  if (delta == 2)
    *red = *red + 1;
}

//////////////////////////////////////////////////////////////////////////
//////                        GLFW public API                       //////
//////////////////////////////////////////////////////////////////////////

GLFWAPI GLFWmonitor** glfwGetMonitors(int* count) {
  assert(count != NULL);

  *count = 0;

  _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

  *count = _glfw.monitorCount;
  return (GLFWmonitor**)_glfw.monitors;
}

GLFWAPI GLFWmonitor* glfwGetPrimaryMonitor(void) {
  _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

  if (!_glfw.monitorCount)
    return NULL;

  return (GLFWmonitor*)_glfw.monitors[0];
}

GLFWAPI void glfwGetMonitorPos(GLFWmonitor* handle, int* xpos, int* ypos) {
  _GLFWmonitor* monitor = (_GLFWmonitor*)handle;
  assert(monitor != NULL);

  if (xpos)
    *xpos = 0;
  if (ypos)
    *ypos = 0;

  _GLFW_REQUIRE_INIT();

  _glfwPlatformGetMonitorPos(monitor, xpos, ypos);
}

GLFWAPI void glfwGetMonitorWorkarea(GLFWmonitor* handle,
                                    int* xpos, int* ypos,
                                    int* width, int* height) {
  _GLFWmonitor* monitor = (_GLFWmonitor*)handle;
  assert(monitor != NULL);

  if (xpos)
    *xpos = 0;
  if (ypos)
    *ypos = 0;
  if (width)
    *width = 0;
  if (height)
    *height = 0;

  _GLFW_REQUIRE_INIT();

  _glfwPlatformGetMonitorWorkarea(monitor, xpos, ypos, width, height);
}

GLFWAPI void glfwGetMonitorPhysicalSize(GLFWmonitor* handle, int* widthMM, int* heightMM) {
  _GLFWmonitor* monitor = (_GLFWmonitor*)handle;
  assert(monitor != NULL);

  if (widthMM)
    *widthMM = 0;
  if (heightMM)
    *heightMM = 0;

  _GLFW_REQUIRE_INIT();

  if (widthMM)
    *widthMM = monitor->widthMM;
  if (heightMM)
    *heightMM = monitor->heightMM;
}

GLFWAPI void glfwGetMonitorContentScale(GLFWmonitor* handle,
                                        float* xscale, float* yscale) {
  _GLFWmonitor* monitor = (_GLFWmonitor*)handle;
  assert(monitor != NULL);

  if (xscale)
    *xscale = 0.f;
  if (yscale)
    *yscale = 0.f;

  _GLFW_REQUIRE_INIT();
  _glfwPlatformGetMonitorContentScale(monitor, xscale, yscale);
}

GLFWAPI const char* glfwGetMonitorName(GLFWmonitor* handle) {
  _GLFWmonitor* monitor = (_GLFWmonitor*)handle;
  assert(monitor != NULL);

  _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
  return monitor->name;
}

GLFWAPI void glfwSetMonitorUserPointer(GLFWmonitor* handle, void* pointer) {
  _GLFWmonitor* monitor = (_GLFWmonitor*)handle;
  assert(monitor != NULL);

  _GLFW_REQUIRE_INIT();
  monitor->userPointer = pointer;
}

GLFWAPI void* glfwGetMonitorUserPointer(GLFWmonitor* handle) {
  _GLFWmonitor* monitor = (_GLFWmonitor*)handle;
  assert(monitor != NULL);

  _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
  return monitor->userPointer;
}

GLFWAPI GLFWmonitorfun glfwSetMonitorCallback(GLFWmonitorfun cbfun) {
  _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
  _GLFW_SWAP_POINTERS(_glfw.callbacks.monitor, cbfun);
  return cbfun;
}

GLFWAPI const GLFWvidmode* glfwGetVideoModes(GLFWmonitor* handle, int* count) {
  _GLFWmonitor* monitor = (_GLFWmonitor*)handle;
  assert(monitor != NULL);
  assert(count != NULL);

  *count = 0;

  _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

  if (!refreshVideoModes(monitor))
    return NULL;

  *count = monitor->modeCount;
  return monitor->modes;
}

GLFWAPI const GLFWvidmode* glfwGetVideoMode(GLFWmonitor* handle) {
  _GLFWmonitor* monitor = (_GLFWmonitor*)handle;
  assert(monitor != NULL);

  _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

  _glfwPlatformGetVideoMode(monitor, &monitor->currentMode);
  return &monitor->currentMode;
}

GLFWAPI void glfwSetGamma(GLFWmonitor* handle, float gamma) {
  unsigned int i;
  unsigned short* values;
  GLFWgammaramp ramp;
  const GLFWgammaramp* original;
  assert(handle != NULL);
  assert(gamma > 0.f);
  assert(gamma <= FLT_MAX);

  _GLFW_REQUIRE_INIT();

  if (gamma != gamma || gamma <= 0.f || gamma > FLT_MAX) {
    _glfwInputError(GLFW_INVALID_VALUE, "Invalid gamma value %f", gamma);
    return;
  }

  original = glfwGetGammaRamp(handle);
  if (!original)
    return;

  values = calloc(original->size, sizeof(unsigned short));

  for (i = 0; i < original->size; i++) {
    float value;

    // Calculate intensity
    value = i / (float)(original->size - 1);
    // Apply gamma curve
    value = powf(value, 1.f / gamma) * 65535.f + 0.5f;
    // Clamp to value range
    value = _glfw_fminf(value, 65535.f);

    values[i] = (unsigned short)value;
  }

  ramp.red = values;
  ramp.green = values;
  ramp.blue = values;
  ramp.size = original->size;

  glfwSetGammaRamp(handle, &ramp);
  free(values);
}

GLFWAPI const GLFWgammaramp* glfwGetGammaRamp(GLFWmonitor* handle) {
  _GLFWmonitor* monitor = (_GLFWmonitor*)handle;
  assert(monitor != NULL);

  _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

  _glfwFreeGammaArrays(&monitor->currentRamp);
  if (!_glfwPlatformGetGammaRamp(monitor, &monitor->currentRamp))
    return NULL;

  return &monitor->currentRamp;
}

GLFWAPI void glfwSetGammaRamp(GLFWmonitor* handle, const GLFWgammaramp* ramp) {
  _GLFWmonitor* monitor = (_GLFWmonitor*)handle;
  assert(monitor != NULL);
  assert(ramp != NULL);
  assert(ramp->size > 0);
  assert(ramp->red != NULL);
  assert(ramp->green != NULL);
  assert(ramp->blue != NULL);

  if (ramp->size <= 0) {
    _glfwInputError(GLFW_INVALID_VALUE,
                    "Invalid gamma ramp size %i",
                    ramp->size);
    return;
  }

  _GLFW_REQUIRE_INIT();

  if (!monitor->originalRamp.size) {
    if (!_glfwPlatformGetGammaRamp(monitor, &monitor->originalRamp))
      return;
  }

  _glfwPlatformSetGammaRamp(monitor, ramp);
}
